Right now the systemd event handling is not actually working at all. This happens because _listener_message_path_is_our_session() has code to check if the event came to our session (e.g. "10") and, under systemd, does this by trying to compare it with the object path, by stripping the /org/freedesktop/login1/session/ prefix. However, under -at least recent versions- of systemd, the session ID part of the path is escaped separately, and following D-Bus rules initial numbers are escaped. In the example above, the obj_path is /org/freedesktop/login1/session/_310, so the comparison actually fails. Port a fix that has been present on various distributions (e.g. Arch) and pieces of software (e.g. cinnamon-screensaver) since at least March 2013. The original author is Peter de Ridder <[email protected]>. The bug and the fix can both be easily verified by running "loginctl lock-sessions".